GALVESTON, Texas (AP) - The crew of a private submarine has gathered data at Flower Garden Banks National Marine Sanctuary as government officials consider expanding the site off the Texas coast.

The effort targeted deep pockets in the Gulf of Mexico, the Galveston County Daily News (http://bit.ly/1NwxxsV ) reported Saturday.

Stockton Rush, a co-founder of Seattle-based exploration company OceanGate, says the sub plunged 1,500 feet and the five-member crew took videos in the proposed sanctuary expansion area. University researchers and Texas Parks & Wildlife Department officials joined the group on its various dives, Rush said.

“We saw worms, crabs and several different invertebrates,” he said. “It’s such an unusual experience to be in a different world.”

The National Oceanic and Atmospheric Administration earlier this year asked for public input about proposed expansion of the Flower Garden, which protects three separate areas with coral reefs about 115 miles off the coast.

The sanctuary could expand to include nine additional banks, enlarging the site from 56 square miles to about 280 square miles, the newspaper reported.

The weeklong trip to the sanctuary was timed up to coincide with the mass coral spawning event that occurs in the reef each year.

Private charter submersibles could become more common in deep regions of the Gulf of Mexico near Texas because oil operations could become more reliant on subs to transport robots for underwater work on rigs and to monitor activity, Rush said.